Drilling apparatus



Feb. 16, 1943.'

c. F. osGooD v DRILLING APPARATUS Filed Aug. 29, 1940. 2 Sheets-Sheet l Feb. 16, 1943.

C. F. OSGQOD DRILLING APPARATUS Filed Aug. 29, 1940 2 Sheets-Sheet 2 fand 4u.; )d NAW, di@

Patented Feb. 16, 1943 were@ DRILLING APPARATUS Charles F. Osgood, Claremont, N. H., assigner to Sullivan Machinery Company, a corporation of Massachusetts Application August 29, 1940, Serial No. 354,741

25 Claims.

This invention relates to drilling apparatus, and more particularly, but not exclusively, to improvements in drilling apparatus of the high speed rotary type.

An object of the present invention is to provide an improved drilling apparatus. Another object is to provide an improved drilling apparatus of the high speed rotary type especially designed for use with diamond core bits. A further object is to provide an improved feeding means for a. drilling apparatus. Yet another object is to provide an improved feeding means which is automatically controlled by the resistance to drill bit rotation whereby the rate of feed is controlled automatically in accordance with the requirements of the work. A further object is to provide an improved feeding means embodying relatively rotatable feeding elements and having improved means actuated by an element of the bit rotating motor for effecting relative rotation between the feeding elements. A still further object is to provide an improved feeding means including a feed-effecting element variably actuated in accordance with the load changes on the bit rotating motor. Another object is to provide an improved feeding means actuated by an element of the bit rotating motor and having improved controlling means whereby the feed is automatically regulated in accordance with the requirements of the work. Other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there is shown for purposes of illustration one form which the invention may assume in practice.

In these drawings:

Fig. 1 is a side elevational view, partially broken away in section, of a drilling` apparatus constructed in accordance with an illustrative embodiment of the invention.

Fig. 2 is an enlarged view in longitudinal vertical section taken through a portion of the drilling apparatus shown in Fig. 1 and illustrating the improved feeding means and the associated control means.

Fig. 3 is an enlarged cross sectional view taken substantially on line 3 3 of Fig. 2.

Fig. 4 is an enlarged cross sectional view taken substantially on line 4-4 of Fig. 2'.

In this illustrative embodiment of the invention there is shown a drilling apparatus of the high speed rotary type especially designed for use with diamond core bits. It will be evident, however, that the invention may be associated with other types of drilling apparatus. The

drilling apparatus disclosed herein generally comprises bit rotating means, generally designated I, supporting and guiding means, generally designated 2, and bit feeding means, generally designated 3.

The bit rotating means I comprises a rotary motor 4, herein preferably a high speed, totally enclosed electric motor, having a casing 5 containing an armature rotor 6 keyed to a shaft 'I journaled Within bearings 8, 8 suitably supported within the motor casing. Carried by the front end of the motor shaft 1 is a chuck 9 for receiving the shank of a drill rod I0 by which a diamond core bit II is carried. The motor casing 5 has a rearward cylindric projection I2 journaled in ball bearings I3 suitably supported within a bore I4 formed in a sliding frame I5. The cylindric projection I2 is retained in position in the bearings by a retaining plate I6 suitably secured to the motor casing projection. The sliding frame I5whas a chamber I'I closed by a rear cover I3 held in position by screws I9, and projecting forwardly from the cover is a cylindric portion 20 extending within the chamber I'I, as shown in Fig. 2. T'ne motor casing has limited oscillatory movement in its bearings with respect to the sliding frame I5, and a relatively heavy coiled torque spring 2I is interposed between the motor casing and the sliding frame. This coiled torque spring surrounds the cylindric portion 2l] and has one end secured by a pin 22 to the retaining plate I6 and its other end secured by a pin 23 to the sliding frame cover. A suitable lubricant seal 24 is arranged within the sliding framebore and sealingly engages the exterior surface of the retaining plate for preventing leakage of lubricant from the bearings. Attached at 25 to the sliding frame cover is a hose 25 for supplying liquid through a conduit 21 extending centrally within the motor power shaft to the drill rod, and the liquid may flow through the drill rod to the drill bit to cool the latter and wash away the cuttings from the bottom of the drill hole.

The supporting and guiding means 2 comprises a guide shell 28 having longitudinal guideways 29 for slidingly receiving lateral guides 3|) integral with the sliding frame I5. The guide shell has a swivel plate 3I adapted to be clamped in the saddle mounting of a conventional drill suport.

p The feeding means 3 comprises a feed screw rotatably mounted in end brackets 33 and 3d carried by the guide shell. The feed screw engages a feed nut 35 journaled in hearings 36 supported within the sliding frame l and the sliding frame cover I8. Fixed to the rear end of the feed screw is a hand crank 3! provided with a suitable lock 38 for locking the hand crank to the guide shell, thereby to hold the feed screw against rotation. The lock may assume various forms and herein comprises a spring-pressed plunger 39 carried by the hand crank and engageable within a locking recess 45] in the rear guide shell bracket 34. The plunger lock is provided with a cam release handle 4i. Similar locking means is provided for the feed nut and herein comprises, guided within a bore 42 in the sliding frame cover i8, a springpressed plunger lock 43 engageable with locking notches 44 on the feed nut for holding the latter against rotation with respect to the sliding frame. The plunger lock i3-is provided with a cam release handle 45 conveniently located at the rear end of the sliding frame. If desired frictional locks, such as frictional locking bands, may be employed instead of the positive locks disclosed. It will thus be seen that during manual feeding of the bit rotating motor, the feed nut may be locked against rotation and during automatic feeding of the bit rotating motor the feed screw may be locked against rotation while the feed nut is released for free rotation.

Means is provided controlled automatically in accordance with the torque changes on the bit rotating motor for effecting rotation of the feed nut relative to the feed screw to feed the drill bit toward the work during the drilling operation. This automatic nut rotating means may assume various forms and herein includes the torque spring 2| and further includes a pawl il pivotally mounted at 48 within a projection i9 integral with the retaining plate I secured to the motor casing. The pawl is yieldingly pressed by a spring-pressed plunger 5i) into engagement with ratchet teeth 5l formed on the feed nut. Other forms of devices such as roller ratchets and similar forms of intermittent gripping devices might be employed in lieu of the pawl and ratchet shown, and instead of a single pawl additional pawls might be used. As the motor casing oscillates within its bearing mounting with respect to the sliding frame during the drilling operation, the pawl is actuated relative to the ratchet teeth to effect step by step rotation of the feed nut in a direction to effect forward feed, the pawls slipping over the ratchet teeth as the motor casing rotates in one direction and engaging the ratchet teeth to effect feed nut rotation when the motor casing rotates in the opposite direction. Oscillation of the rnctor casing is controlled by the coiled torque spring, and as the load on the motor increases, the tension of the torque spring is correspondingly increased, and the torque spring, when the load on the motor decreases, effects rotation of the motor casing in the feed nut rotating direction.

The general mode of operation of the improved drilling apparatus is as follows. When drilling apparatus has been set up in proper position with respect to the working face with the swivel plate suitably clamped in position in the support saddle, the operator may operate the plunger lock 43 to lock the feed nut 35 against rotation and release the plunger lock and the bit rotating motor may then be fed forwardly along the shell guideways by means of the hand crank 3l of the feed screw 32. When the drill bit il has been fed against the working face and the drill bit is resisted by the work, the operator may lock the feed screw 32 against rotation by the plunger lock 33 and release the plunger' lock 43 to permit free rotation of the feed nut 35. The resistance to drill bit rotation causes the motor casing to rotate in its bearing mounting relative to the slide frame l5, and as the resistance to drill bit rotation increases a substantial tension is built up within the torque spring 2i and the tension of the torque spring varies in accordance with the torque changes on the bit rotating motor. As the drill bit pene- .trates the work, the load on the bit decreases,

thereby decreasing the motor torque and permitting the tension of the coil spring to rotate the motor casing in a direction to move the pawl 41 to eXert a thrust upon the ratchet teeth, the pawl acting on the ratchet teeth to rotate the feed nut in a direction to effect feed of the drill bit toward the work. The oscillatory movement of the motor casing relative to the sliding frame effects step by step rotation of the feed nut, and since the turning movement of the motor casing varies in accordance with the motor torque and the resistance to bit rotation, the rate of feed is varied automatically in accordance with the requirements of the work. As the feeding pressure on the drill bit increases, the lead on the bit rotating motor is correspondingly increased, resulting in a corresponding increase in the tension of the coiled torque spring, and as the motor torque decreases due to penetration of the work by the drill bit, the coiled torque spring acts in a direction to move the pawl rela.- tive to the ratchet teeth to rotate the feed nut in the forward feeding direction.

It will be understood that increases in motor torque suiicient to effect rotation of the motor casing in the direct-ion necessary to cause the pawl 47 to reengage the ratchet Wheel 35 in a position to exert a new thrust thereon may be caused as often as may be necessary by turning the hand crank 3'! and rotating the feed screw 32 in a forward feeding direction sufficiently to increase the pressure of the bit on the bottom of the hole to the necessary degree adequately to increase the motor torque, the feed nut being lockable duling this operation if desired. When drilling rock of very uniform hardness and resistance to cutting this operation may be necessary periodically, with automatically effected and controlled feed during the intervals. When the rock is of uneven consistency rearward rotary movements of the motor casing necessary to reposition the pawl for a new action at a different,

place on the ratchet wheel may take place upon increased resistances to drilling, without the manual turning of the feed screw.

It is accordingly evident that the drill bit is initially fed toward the work by the feed screw until the feeding pressure on the drill bit is sucient slightly to overload the motor, causing the motor casing to rotate in a direction to increase the tension of the coiled torque spring. The feed screw is then locked against rotation and the feed nut lock is released, and as the drill bit penetrates the work the motor torque is reduced so that the coiled torque spring may act to rotate the motor casing in the opposite direction, causing the pawl to engage the ratchet teeth and rotate the feed nut. It will thus be seen that `as the torque changes on the bit rotating motor occur, the motor casing oscillates relative to the sliding frame, and this oscillatory movement effects step by step rotation of the feed nut through the pawl and ratchet in` a direction to effect feed of the drill bit toward the-work. As the resistance to bit rotationA and the load on the bit rotating motor vary, the rate of feed and the feedin-g pressure on the drill bit are automatically correspondingly varied.

When it is desired to feed the bit rotating motor in the reverse direction relative to the guide shell, the feed nut is locked against rotation by the plunger lock 43 and the feed screw lock $9 is released. The feed screw 32A may then be manually rotated by the hand crank 31 to effect feed of the bit rotating motor rearwardly. No automatic control of the reverse feed is possible, and, as a matter of fact, any control dependent on bit rotation would be undesirable since rotation of the drillv bit must be discontinued during withdrawal of the drill bit from the drill hole to prevent Whipping of the drill rod and possible breakage of the diamond bit by engagement with the hole walls.

As a result of this invention it will be noted that an improved drilling apparatus is provided having improved feeding means automatically controlled by the resistance to drill bit rotation whereby the rate of feed is controlled automatically in accordance with the requirements of the work. It will further be evident that by the provision of the improved feeding means, the torque changes on the bit rotating motor automatically regulate the rate of feed. Further, by the provision of the oscillatory motor casing and the driving connections between the oscillatory motor casing and the rotatable feed nut, the feed of the bit rotating motor is effected in an extremely efficient and simple manner. Other uses and. advantages of the improved drillingV apparatus will be cl-early apparent to those skilled in the art.

While there is in this application specically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a casing, a support for said motor and on which the motor casing is mounted for oscillatory movement, feeding means for the drill bit including a feeding element operatively con-- nected to said support, and means actuated by the oscillatory movement of the motor casing during the drilling operation for actuating said feeding means.

2, In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a. casing, a support for said motor and on which said motor is mounted for oscillatory movement, a torque spring connected between said motor casing and said support for controlling the oscillatory movement of the mot-or casing, feeding means for the drill bit including a feeding element operatively connected to support, and means actuated by the oscillatory movement of said motor casing during the drilling operation to effect actuation of said feeding means.

3. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a casing, a support for said motor and on which the motor casing is mounted for oscillatory movement, a torque spring connected between said motor casing and said support for controlling the oscillatory movement of said motor casing whereby variations in the resistance to bit rotation automatically control the oscillatory movement of thefmotor casing, feeding means for the drill bit including a feeding element operatively connected to said support, and means actuated by the oscillatory movement of the motor casing during the drilling operation to effect actuation of said feeding means whereby the rate of feed is controlled automatically in accordance with the requirements of the work.

4. In a drilling apparatus, the combination comprising a rnc-tor for rotating a drill bit, said motor having a casing, means for mounting the casing of said motor for oscillatory movement, and means actuated by the oscillatory movement of the motor casing for feeding the drill bit toward the work.

5. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a casing, meansV for mounting the casing of said motor for oscillatory movement,

. and means including an intermittent grip mechanism actuated by the oscillatory movement of the motor casing for feeding the drill bit toward thework.

6. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said: motor having a casing, means for mounting the casing of said motor for oscillatory movement, a coiled torque spring for controlling the oscillatory mov-ement of the motor casing whereby variations in the resistance to drill bit rotation automatically control the oscillation of the motor casing, and means actuated by the oscillatory movement of the motor casing for feeding the drill bit toward the work whereby the rate of' feed is controlled automatically in accordance with the requirements of the work.

7. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a casing, a sliding support for said motor, a guide shell on which said support is slidably guided, means on said sliding support providing a bearing mounting for the casing of said motor for journaling the motor casing for oscillatory movement, means for feeding said supportrelative to the guide shell including a rotatable feeding element journaled on said support, and means actuated by the oscillatory movement of the motor casing for rotating said feeding element..

8. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a casing, a sliding support for said motor, a guide shell on which said support is slidably guided, means on said support providing a bearing mounting for the casing of said motor for journaling the motor casing for oscillatory movement, feeding means including relatively rotatable feeding elements one mounted cn said guide shell and the other journaled on support, and means actuated by the oscillatory' movement of the motor casing for relatively rotating said feeding elements.

9. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a mot-'able casing, means for mounting the motor casing for limited movement, feeding means for the drill bit, and means actuated by the movement of said motor casing relative to said mounting means for actuating said feeding means.

10. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a movable casing, means for controlling the movement of said casing whereby variations in the load on the motor automatically vary the movement of said casing, feeding means for the drill bit, and means actuated by the controlled movement of the motor casing for actuating said feeding means whereby the rate of feed is controlled automatically in accordance with the requirements of the work.

11. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having an oscillatory element, means for controlling the oscillation of said motor element whereby variations in the load on the motor automatically vary the oscillatory motion of the motor element, feeding means for the drill bit, and means actuated by the oscillatory motor element for actuating said feeding means whereby the rate of feed is controlled automatically in accordance with the requirements of the work.

12. In a drilling apparatus, the combination comprising a rotary motor for rotating a drill bit, automatic feeding means for said motor including mechanically interengaged, relatively rotatable, cooperating feeding elements, and means operable solely by said motor during automatic feeding and controlled automatically by the load changes thereon for actuating said feeding means whereby the t is fed automatically at a rate suitable to the requirements of the work.

13. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said m-otor having an element which provides the reaction necessary for the rotation of the drill bit, supporting means for said motor on which said motor element is mounted for limited movement relative to said supporting means, means for holding said motor element against said relative movement but adapted when overloaded to permit movement of said element relative to said supporting means, and feeding means driven by said movable motor element for feeding the drill bit toward the work during the drilling operation.

14. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having an element which provides the re action necessary for the rotation of the drill bit, supporting means for said motor on which said motor element is mounted for limited rotary movement relative to said supporting means, means for holding said motor element against said relative rotary movement but adapted when overloaded to permit rotary movement of said element relative to said supporting means, and feeding means driven by said rotary motor element for feeding the drill bit toward the work during the drilling operation.

15. In a drilling apparatus, the combination comprising a rotary motor for rotating a drill bit to effect drilling with a boring action, automatic feeding means for said motor driven by the latter and including mechanically interengaged, relatively rotatable, cooperating feeding elements, said motor constituting the sole power source for said feeding means during automatic feeding, and means responsive to the resistance to drill bit rotation for automatically controlling the rate of feed in accordance with the requirements of the work.

16. In a drilling apparatus, the combination comprising a motor for actuating a drill bit, said motor having an oscillatory motor element, means for mounting said motor element for limited oscillatory movement relative to said motor element mounting means, and means actuated by the oscillatory movement of said motor element relative to said mounting means for feeding the drill bit toward the work.

17. In a drilling apparatus, the combination comprising a motor for actuating a drill bi-t, said motor having a movable motor element, means for mounting said motor element for limited movement relative to said motor element mounting means, feeding means for the drill bit, and means actuated by the movement of said motor element relative to said mounting means for actuating said feeding means.

18. In a drilling apparatus, the combination comprising a motor for actuating a drill bit, said motor having a movable motor element, means for controlling the movement of said motor element whereby variations in the load on the motor automatically vary the movement of said motor element, and means actuated by the controlled movement of said motor element for actuating said feeding means whereby the rate of feed is controlled automatically in accordance with the requirements of the work.

19. In a drilling apparatus, the combination comprising a motor for actuating a drill bit, said motor having a movable motor element, a support for said m-otor on which said motor element is mounted for limited relative movement, feeding means for the drill bit including a feeding element operatively connected to said support, and means actuated by the movement of said motor element relative to said support during the drilling operation for actuating said feeding means.

20. In a drilling apparatus, the combination comprising a motor for actuating a drill bit, said motor having a movable motor element, a support for said motor on which said motor element is mounted for limited relative movement, resilient means connected between said movable motor element and said support for controlling the movement of said motor element relative to said support, feeding means for the drill bit including a feeding element operatively connected to said support, and means actuated by the controlled movement of said movable motor element relative to said support during the drilling operation for actuating said feeding means.

21. In a drilling apparatus, the combination comprising a motor, supporting means for said motor, said motor having relatively rota-table motor elements one of which is a reaction element and both mounted on said supporting means for movement relative thereto, a drill bit, feeding means for said drill bit, means for operatively connecting one of said motor elements to said drill bit for actuating said bit, and means for operatively connecting said other motor element to said feeding means for actuating the latter.

22. In a drilling apparatus, the combination comprising a motor, a supporting means for said motor, said motor having relatively rotatable motor elements one of which is a reaction element and both mounted on said supporting means for movement relative thereto, means for controlling the movement of said reaction motor ele-- ment relative to said supporting means, a drill bit, feeding means for said bit, means for speratively connecting said reaction motor element to said feeding means for actuating the latter, and means for operatively connecting the other motor element to said drill bit for actuating the latter.

23. In a drilling apparatus, the combination comprising a motor, supporting means for said motor, said motor having relatively rotatable motor elements one of which is a reaction element and both mounted on said supporting means for movement relative thereto, means for controlling the movement of said reaction motor element relative to said supporting means Whereby variations in the load on the motor automatically vary the movement of said reaction motor element, a drill bit, feeding means for said bit, means for operatively connecting said reaction motor element to said feeding means for actuating the latter whereby the rate of feed is controlled automatically in accordance with the requirements of the work, and means for operatively connecting the other motor element to said drill bit for actuating the latter.

24. In a drilling apparatus, the combination comprising a drill bit, automatic feeding means for said drill bit including mechanically interengaged, relatively rotatable, cooperating feeding elements, a motor common to the actuation of said drill bit and said feeding means and constituting the sole power source for the latter during automatic feeding, said motor moving bodily with sai-d drill bit during the drilling operation, `and means operatively connected to an element `of said motor and controlled automatically by the load changes on said motor for actuating said feeding mns whereby the drill bit is fed automatically in accordance with the requirements of the Work.

25. In a drilling apparatus, the combination comprising a rotary drill bit, automatic feeding means for said drill bit including mechanically interengaged, relatively rotatable, cooperating feeding elements, a motor common to the actuation of said drill bit and said feeding means and constituting the sole power source for the latter during automatic feeding, said motor moving bodily with said drill bit during the drilling Operation, and means responsive to the resistance to drill bit rotation for automatically controlling the rate of feed in accordance with the requirements of the Work.

CHARLES F. OSGOOD. 

